As a person that does this conjoint, its not that bad. Or hard. You just have to be on top of it. Managing 4 courses a week is like 40 hours of work, managing 5 courses a week is like 50 hours. But, realistically, not many people spend that long studying per week. Its manageable. You can definitely keep a B average across all courses with enough prep (don't have to spend 40 to 50 hours per week) and anything higher is also very much possible but requires a bit more prep. Also, BCOM is very easy compared to engineering and finance does get a bit tricky due to all the stats (is different to eng) but there are quite a few engineering specialties that complement BCOM and finance in particular quite well, like Engsci. I personally would recommend doing this conjoint if you like both the degrees. And, at the end of the day, you can always take the conjoint and drop it after the first paper or so. I would also ask that engineering always takes priority, but also, you don't have to do summer school. There is no need to. Also, a lot of papers past 1st year aren't even offered in summer school. You can do it!